A thought on retractable spoilers

[aerohead]

Originally Posted by freebeard

For some reason your post has no Thanks button. Thanks.

Was this ever built?

So far,as best as I've seen,there's nothing in the public domain which demonstrates that the concept ever went beyond the schematic.
When the T-100 was still John Gilkison's,I sewed up an envelope out of Naughahyde,attached to a box,with a Westfalia 12-VDC ventilation fan for inflation.We drove it on a camping trip in New Mexico and with a 1/2-tonneau,and a cargo box on the floor of the bed we saw over 30 mpg.
I'd used expandable fabric and it stretched completely out of proportion,but still returned interesting numbers.
I'm going to try a 1-foot inflated section for the stinger on the September trip.This will get me to the 5-foot DOT length limit for an experimental.
http://ecomodder.com/forum/member-ae...lkisons-t.html

[ecomodded]

Originally Posted by aerohead

You can also leave the roof as is,and just add a false K-form structure to slow the contour.

Thanks for the input and template , if I was to start the Template @ the windshield top and have it taper back into the boat tail profile , it would shorten the length of the required profile.

In the above photo the added section would start at the top of the windshield for the highest point tapering back into the boattail profile

another way to look at it ..
If the Beetle was backed up in the photo until the windshield was at the profile's start, it would shorten the length a fair amount.

I could leave the windshield as is and hack just the roof and hatch.



I could shrink the car into a boat tail

edit: It would require a Roll Cage and certification and more money then I have to spare at the moment. mo money

[aerohead]

Originally Posted by ecomodded

Thanks for the input and template , if I was to start the Template @ the windshield top and have it taper back into the boat tail profile , it would shorten the length of the required profile.

In the above photo the added section would start at the top of the windshield for the highest point tapering back into the boattail profile

another way to look at it ..
If the Beetle was backed up in the photo until the windshield was at the profile's start, it would shorten the length a fair amount.

I could leave the windshield as is and hack just the roof and hatch.



I could shrink the car into a boat tail

edit: It would require a Roll Cage and certification and more money then I have to spare at the moment. mo money

Here's an image adapted from Koenig-Fachsenfeld's book.The fourth image down depicts a body who's roofline descends right from the windshield header.
I can't vouch for it.It's never done,even in racing cars.There's always a 'soft' peak,where the boundary layer is given ample time to reverse its camber.

Volkswagen corrects the Beetles roof some with the Audi TT.
They take it further with the Porsche Panamera.
VW's best (in elevation)is perhaps the Bugatti Veyron and the latest Lamborghini's,like Aventador.
All have very forgiving contours to protect against separation,as this would also induce rear lift.Something potentially life-threatening in the supercars.
While you're waiting on cash for the project,check out VW's high-end cars,and also,Freebeard has done some really nice renderings of Beetles with modified rooflines.Well worth the look.
I've got 37 scans waiting.If Al can do them,I'll have some additional images to share.

[freebeard]

About those renderings. I would point to Compact camper alternative:.... If I could detach the hatch in that model, I'd have it open like a Type II ambulance (hinged on the bottom) and fill the gap with ribs and canvas like an old Model T Touring.

[The reason the Thanks button wasn't working was you can only press it once. Who knew?]

Maybe there's no published examples in the automotive world, but it turns out Dumbo Octopuses do it.


Plus which:


Edit: Here're these ones, too. Half-circular cross section instead of a squircle.


Coanda nozzle vs high-tailed stinger:

[aerohead]

Yes,octopi really rock!
I have a still taken of an octopus by one of Jacques Cousteau's crew and its tentacles form a beautiful ,streamlining boat tail.

[ecomodded]

I had thought I would leave a little soft curve , perhaps half the size of a the templates depiction , as the boat tail itself would be smaller. I would try to keep it to scale / proportion.

Most designs seem to have the raised portion set at the end of the roof line , I want to move it forward , have it blend off the front of roof instead of the rear.
Figure 7 is actually the profile that I want to do.

Fig. 7 looks sound to me , opinions needed !


(Freebeard I am going to look for your Beetle designs)

[aerohead]

Originally Posted by ecomodded

I had thought I would leave a little soft curve , perhaps half the size of a the templates depiction , as the boat tail itself would be smaller. I would try to keep it to scale / proportion.

Most designs seem to have the raised portion set at the end of the roof line , I want to move it forward , have it blend off the front of roof instead of the rear.
Figure 7 is actually the profile that I want to do.

Fig. 7 looks sound to me , opinions needed !


(Freebeard I am going to look for your Beetle designs)

The 7th figure from the top is the Koenig-Kamm 'Kamm back' contour and a good choice.
Since the roof would begin at the windshield header it would be significantly lower than the Beetle's original roof peak,and since it is significantly forward of the original max camber position,you're killing two birds with one stone.
It would generate some interesting numbers at the gas pump.

[ecomodded]

thanks frebeard the new yellow beetle is a pretty close representation to what I have in mind also , I Imagine the Koeing-Kamm to be curved in a similar manner to that design.

Now I have a template and design to learn about , Thanks a Boat load Areohead , I have a clearer direction now , the Koenig-Kamm. I am going to start a thread on just this design and expand on it.

And thank you Serialkiller for the space I used asking questions on your thread !

[freebeard]

Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - freebeard's Album: photoshops. One other New Beetle there. I trust the new thread will appear in Aerodynamics.

Our friend, the Tartigrade.